a fun project. A set of 6?
The balls are solid color and each is paired with a mallet with the same color stripes on the head and sometimes the handle. The wicket pegs get all the stripes.
I have not made a croquet set but have colored quite a few balls.
when I do these multiple I would turn a a couple of head designs and choose the one I like. Copy that one and make a few extras and pick the 6 I like the best.
I would use airbrush and paint. Can be brushed on if you don’t have an airbrush. But you could use dyes. On the heads and stakes this you can turn the edges of the dyed bands after you do the dying to get a crisp line. With airbrush paints you can mask the lines or turn the edges.
for a final finish I would use Waterlox partly because I use it a lot. It is used a floor finish so it takes a lot of wear. Waterlox does not change color very much. White wood still looks almost white.
Is water resistant enough to leave the set out in the rain for a day.
this is ball that was dyed green, masked off, sandblasted then airbrushed with orange and a bit of red.
for the heads I would drill the handle mortis on the drill press. Using a vee block.
Vee block is a 2x4 run through the table saw twice with the blade at 45 degrees to rip out a resting place for the mallet heads to drill the mortise for the handle.
This is how I drill gavel heads.